Such a gas turbine is known from EP 1 118 806 A1. A freely projecting flexural extension is provided for sealing off a gap delimited by two partially overlapping wall segments. Under thermal action, the flexural extension flexes in such a way that it closes the gap.
EP 896 128 discloses a sealing element for a gas turbine. The gas turbine has a guide blade ring consisting of adjacent turbine guide blades which form an annular hot-gas duct. Platforms are arranged on the turbine blades for the inner and outer delimitation of the hot-gas duct. Directly adjacent platforms form, with their end faces lying against one another, a gap which is sealed off by means of a sealing element. For this purpose, a groove is introduced in each case in each end face, said grooves lying opposite one another and the sealing element being inserted into them. The sealing element, of C-shaped cross section, projects in each case with one of the two bent ends into a groove in such a way that the two arms of the sealing element which extend transversely with respect to the groove bottom bear in each case against a flank of the groove and thus seal off the gap between the two adjacent platforms. The working fluid flowing in the hot-gas duct is thus prevented from leaving the duct through the gap.
Furthermore, a sealing element is known from DE 100 44 848, which seals off a gap formed between two static turbine parts. The sealing element is likewise inserted in two grooves lying opposite one another, but, in contrast to EP 896 128, has a different geometry. The action and function of this sealing element are identical to those of the abovementioned sealing element.
When the gas turbine is in operation, thermal expansions arise on the components acted upon by hot gas, such as the guide blades and their platforms, and may lead to a displacement of the components with respect to one another.
In the case of a shear displacement directed parallel to the gap, the known sealing elements allow only relatively small displacement travel.